Analysis of Erlang capacity for DS-CDMA systems supporting multi-class services with the limited number of channel elements

In practice, the DS-CDMA system is equipped with a finite number of channel elements (CEs) that performs the baseband spread signal processing for a given channel in the base station. In this situation, the call blocking can be caused not only by the insufficient number of channel elements but also by the limit of available traffic channels. We focus on analyzing the effect of the limited number of CEs on the Erlang capacity of multimedia DS-CDMA systems in the reverse link when the CDMA cells are sectorized with 3 sectors. For the performance analysis, a multi-dimensional Markov chain model is developed. As a result, the more CE results in the larger Erlang capacity. However, the Erlang capacity is saturated after a certain value of CEs where the call blocking is mainly caused by the insufficient channels per sector